Fuel injector apparatus for diesel engines



INVENTORS Aura/v1? Jinan-z,

2&4 ATTORNEYS Apr1l21, 1953 H M KOLSTEE ET AL 2,635,922

FUEL INJECTQR APPARATUS FOR DIESEL ENGINES Filed Oct. 2, 1951 2 SHEETS-SHEET l 7 Mums/Hasn't,

mm Jnw f. TUJCHE/P- April 1953 H. M. KOLSTEE ET AL FUEL INJECTOR APPARATUS FOR DIESEL ENGINES 2 SHEETS--SHEE'1' 2 Filed Oct. 2, 1951 INVENTORS A? Hams MAozsME/bvra/v IF/KoLSrEE,

Alva Jsmv 5. 7050/51??? BY (369M q p 4,

ATTORNEYS Patented Apr. 21, 1953 FUEL INJECTOR APPARATUS FOR DIESEL EN GINES Hans M. Kolstee, West Springfield, Mass., Anton F. Kolstee, The Hague, Netherlands, and Jean E. Tuseher, Ivry-sur-Seine, France Application October 2, 1951, Serial No. 249,278

4 Claims. 1

This invention relates to an apparatus for injecting fuel into the combustion space of various types of diesel or semi-diesel engines and has for an object to provide the power for fuel injection from the compression of air in the engine cylinder produced during the compression stroke thereof.

Another object is to provide improvements in the construction and function of such a device, a prior example of which is disclosed in Netherlands Patent No. 42.231 dated 1937 to J. E. Tuscher.

A further object is to provide a low cost integrated mechanism, less expensive to make than an ordinary separate injection pump, injector, and high pressure connecting tube for diesel engines and to provide a unit which may be regulated and maintained in a more simple manner.

A further object is to provide a higher injection pressure for the working cylinders of a diesel engine thereby resulting in improved combustion and the successful use of low grade fuel oils.

The unit as will be disclosed has a wide range of application for high or medium pressure engines and for fast or slow running speeds since a small mass of moving parts permits a high frequency. In using the unit on a two-stroke crankcase scavenging engine, no cam shaft is required.

The above and other objects and advantages will be apparent from the following detailed disclosure of an embodiment of the invention as shown by the accompanying drawings, in which:

Fig. 1 is a sectional view of the apparatus embodying the invention and mounted in position on the cylinder head of an engine;

Fig. 2 is a top plan of the device;

Fig. 3 is a section on line 3-3 of Fig. 1;

Fig. 4 is a section on line 4-4 of Fig. 1;

Fig. 5 is a fragmentary section at one end of the device to illustrate means for hand pumping; and

Fig. 6 is a fragmentary detail view to show the fuel metering recess to regulate the quantity of fuel injected.

The apparatus shown is designed to utilize the compressed air in the working cylinder of a diesel engine by entrapping the air in a chamber having a piston housed therein, the piston being movable against a plunger member which is adapted to entrap a charge of fuel between the tip end :of the plunger and the opposing tip end of a .slidable spring pressed counter-plunger member. The two plungers with the fuel be tween the opposed ends thereof are movable as a unit by the piston. At the end of the com pression stroke and during the beginning of the combustion stroke the entrapped oil is released under high pressures to open the spray valve of the atomizing nozzle and be then injected into the engine cylinder.

The new unit is mounted in the cylinder head of the diesel engine as, for example, in the location of an existing injector. As illustrated it comprises in general a horizontally disposed injection pump and a vertical connector mounting assembly. A spray valve and tip with nozzle projecting through the wall of the engine cylinder is at the lower end of the connector assembly.

In the drawings the combustion space is indicated at I in an engine cylinder with water jacket indicated at 2. The latter has an opening 3 through its wall, the opening being shouldered adjacent the lower end at 4 to receive the mounting structure as will be described. A spray tip 5 with fine atomizing spray orifices 6 is suspended in the lower reduced portion 1 of the opening 3. Tip 5 is threaded on a reduced lower end of a vertical connector piece 8 and is sealed with a gasket 9. A chamber H1 is formed in the tip and a spring held check valve H is shown in the chamber seated against an inlet port theretofrom a central longitudinal fuel canal I2 of the connector piece 8. i

The connector 8 also has a reduced upper end I3 threaded to a pump body member I4. Canal !2 is connected to a canal I5 of the body I4 and forms a fuel injection line as will be later described.

Snugly encasing the connector 8 in opening 3 is a tubular support housing I6. The lower inwardly flanged end of the housing is supported by the shouldered portion at 4 of the opening. The upper outwardly flanged end of housing I6 is received in an enlarged recess of body H! to support the same and is held tightly thereagainst with asealing ring by an externally threaded collar ll threaded against said flange. Collar I! is outwardly flanged at the foot IB thereof and against the flange a ring is is clamped. Ring I9 is secured by bolt stud and nut assemblies 20 to the water jacket 2 as shown. Thus the nozzle assembly and pump body I 4 with the parts thereof are mounted in operative position being supported on the engine cylinder by the housing support l6.

It will be noted that between the periphery of spray tip .5 and the reduced end I of opening 3 an annular passage is provided. This passage is in open communication with the combustion space of the cylinder and at the top of the passage is joined with another annular passage between the hexagonal outer wall portion of the spray tip (see Fig. 4) and the inner housing wall at the lower end of housing H5. As shown by Figs. 1 and 4 the connector'piece 8 also has milled channels 2| cut longitudinally in the outer surface thereof from top to bottom to serve as passages leading from the lower end of the housing to the upper end of the same. end of the housing the shoulders of the connector piece 8 forming the reduced end |3 thereof are spaced from the wall of the body M to provide an annular passage leading to a vertically directed canal 22 formed in the body M. The canal 22 is in communication with a horizontal canal 23 leading to one end of the body |4 as to the left in Fig. 1.

At said end of the body l4 a piston chamber 24 with piston25 is provided, the pressure side of the chamber being formed by a cap 2 3 secured by bolts as at 2'! to the body and sealed by a gasket connection at 28. Cap 23 has a central opening in which a plug 29 is threaded. Plu 29 may be removed for hand pumping of the unit for testing etc. as will be described.

The gasket 28 is perforated at the lower side thereof and cap 26 is also'provided with an elbow canal 35 to complete the open pressure line from combustion space I to the pressure side of the piston chamber. A cleaning screw plug 35' in cap 25 is provided for the elbow canal 30.

Piston 25 is movable in chamber 24 under compression of air from the combustion space against a plunger 3|, the enlarged head 32 of which is rounded and biased against the piston by a spring 33 seated on a collar 34 of the plunger adjacent head 32. Spring 33 is seated at its other end in a flanged shoulder 35 of a plunger sleeve 35. Sleeve 36 is mounted in a cylindrical bore of the body I4, the bore being in axial alignment with the piston chamber. The sleeve has a plunger bore and extends to the opposite end of the body l4. Shoulder 35 of the sleeve 36 is seated against the annular abutment of the piston chamber at its inner end.

The tip end of plunger 3| is approximately midway of the sleeve bore and is spaced from the tip end of a counterplunger 31 also held in the bore.

At the other end of the sleeve, plunger 31 extends outwardly of the pump body l4, its outer end portion being provided with a toothed pinion 38 (see Fig. 3) and its tip end being received in a central recess 39 of a spring seat 40. A pinion housing 4| is bolted as at 42 to theend of body 14 and carries a reciprocable gear rack 43 with rack 44 for rotating counterplunger 31 in the sleeve as will be described.

The spring seat 43 is mounted in the cupshaped end of housing 4|. Threaded on the outer wall of the cup is an end cap 45, encasing an outer spring seat 45 holding a spring 4! between seat 45 and seat 40. Seat 46 on its outer side has a central recess receiving the end 50 of a plug mounted in cap 45 in alignment with the counterplunger. Plug 51 also carries on the outside of the cap a timing lever 52 having a pin 53 offset from the plug and received in a recess 54 of the cap for turning the cap on its threaded engagement with the pinion housing 4|.

The movable parts of the unit are shown in a position ofrest by Fig. 1., In the space between the plunger tips is a fuel inlet port at 55 immediately adjacent the tip end of plunger 3|.

At the upper '4 Suitable canals (not shown) are provided in body l4 and sleeve 35 from the fuel feed connection to the body M at 55 (Fig. 2). In the tip end portion of counterplunger 31 a helical metering recess 55 is shown. The recess is adapted to connect the space between the plunger tips with a fuel injection canal 51 in the body of the sleeve 36. Canal 51 is connected at right angles to a canal 58 milled in the side of sleeve 36 which in turn is connected to a transverse canal 59 drilled through the body of the sleeve and in axial alignment with canals I5 and I2 of the body I4 and connector piece 8 respectively.

Outlet canal 59 is separated by the bore of the sleeve and passage'of fuel therethrough is blocked in the rest position of plunger 3| in the bore. Spaced from the tip end of the plunger BI is an annular groove 53 in the periphery of plunger 3| adapted to be in registration with canal 59 when the plunger 3| is moved by pressure in the combustion space exerted against piston 25.

As will be appreciated the unit is operative during the compression stroke of the working cylinder of the engine and the beginning of the combustion stroke. Upon commencement of the compression stroke pressure begins to build up against piston 25 by the open communication with combustion space I through the annular passages at l and the lower end of support l6, channels 2| of connector 8, and canals 22, 23, and 3!]. This pressure moves piston 25 against the head of plunger 3|, overcoming the pressure of spring 33. The plunger moves axially in sleeve 35 towards the counterplunger 31 and initially closes off fuel inlet port 55. A metered quantity of fuel may thus be entrapped between the tip ends of the plungers. a

As pressure in combustion space increases, the entrapped. fuel is placed under pressure. Near the end of the compression stroke the pressure is sufficient to overcome the combined resistance of plunger 33 and counterplunger spring 47. Plunger 3|, the fuel, and counterplunger 31 are moved axially in the sleeve by the piston 25 towards end cap 45. The helical metering recess 53 is connected with discharge injection canal 51 and the pressure of the entrapped fuel between the plungers is transmittedthrough the oil filled outlet passages to the spray valve i. e. canals 51, 58, 59, groove 55, canals l5, and I2.

- It will be appreciated that as soon as the annular groove 65 spaced from the tip end of plunger 3| unblocks' canal 59 (which is timed to occur just before the piston of the engine cylinder passes its top dead center at the end of the compression stroke), the fuel under pressure will escape from the spacing between the ends of the plungers, lift check valve i, be injected through the atomizer orifices 5, and sprayed into the combustion space.

During the injection of fuel through the spray tip the counter-plunger 31 will move toward plunger 3| due to the pressure of spring 41 and passage of fuel through the discharge canals, while plunger 3| will continue to move toward the counter-plunger due to the higher combustion pressure in the combustion space I. This movement of plunger 3| continues until the collar 34 of spring 33 abuts the adjacent end of sleeve 35. In this position of the plunger 3| the annular groove 65 and spaced portions of canal 59 will be entirely in line and fuel oil will unrestrictedly flow through the discharge canals.

From the above action of plunger 3| it'will be appreciated that fueloil is not injected quantitatively at full force at the tbeginningof the combustion stroke :(the annular groove on plunger 31 not yet being entirely %in line with canal 59') Counter-plunger 3.1 will during the period .fuel injection continueto move in the direction of p1unger3l until the port of discharge canal 51 :is closed off. It will not move further with the engine at less than full speed until the :end of the combustion strokeof the cylinder when the spring -'4'! .is strong enough to "overcome the pressure 'onpiston .25. It will beappreciatedfrom the :form of thehelical metering recess 56 .thatit will be possible to 'vary'thetimingfor'the opening and zclosingiof the discharge port and this may be accomplished by rotating the counterplungerjin the sleeve .bore. Rotation of the "counter-plunger is effected by sliding the rack bar 43 in housing 4| to rotate the pinion .38. The pinion is encased in the housing 4! and counterplunger 31 :is axially movable therein, the counterplunger being fitted with-an enlarged flat sided portion slidably held in the oppositely fiat sided bore of the pinionas shown in Fig.3.

Thus by movement of the rack thecounter plunger iiserotated in the sleeve bore to register the .recess 56 with discharge canal 51. More'or less fuel oil as desired can be supplied for injection and the speed of the engine regulated bymovingthe rack bar.

At theen'd of the combustion stroke the pressure on piston i 25 eventually becomes lower than the pressure of the plunger spring 33 and the piston 25 with plunger 13! resumes a position of :rest. The .fuel inlet port 55 is thus open to the :space between the plunger tips to admit a fresh supply of fuel. Spring 47 :has previously restored counter-plunger 31 to its position of rest.

In order to regulate the moment at which the injection begins, the timing lever 52 is provided. By turning this lever, end cap is turned onitsthre'aded connection with housing 4|. The tension of spring 41 is thus made greater or lesser to resist to a greater or lesser degree the pressure imposed on piston 24. Timing of the fuel injectioncan thus. be regulated. The retarding effect of a slight decrease in prevailing compression end pressures in the engine cylinder (caused by wear of the engine piston) can also be neutralized by reducing the pressureof spring 41 in loosening the cap 45. In order to prevent the cap from workingloose by vibration a pointed spring 65 is fixed at one end on body 4| with its tip 65 hearing on a grooved rim of the cap.

It will be realized that the injection pressures possible with the mechanism as disclosed can be determined by the relative dimensions of the surface of piston 25, the tip end surface of plunger SI and the tension of spring 41. The maximum quantity of fuel to be injected may be determined by the diameter and stroke of the counter-plunger 31.

It will also be apparent that the surface area of piston 25 is necessarily of appreciably greater magnitude than the end surface area of the tip of plunger 31 in order to create the desired fuel injection pressure. The strength of spring 4'! will necessarily be of a mangitude to create sufficient resistance to pressure at the tip end of counter-plunger 31 and contain the entrapped fuel prior to its release into the injection canals.

By varying the relationships the :unltcan Ebezused on high pressure prmediumpressure engines.

In order to promote the sealing of piston 2.5 in its chamber and further to cool the same 'a'lubrication inlet maybe provided as :at 61 (Fig. 2) .in the wall of body member H. A discharge outlet is indicatedat 68. These openings may bessuitably connected the pressure lubricating system of the engine proper. :In the eventseparate lubrication passagesarenot considered necessary, especially onmedium pressure engines, it will be appreciated that a certain degree of lubrication can be sufliciently efiected by .fuel :oil leakage between the plunger 3il and sleeve 3.6.

In Fig. 5 a fragmentary section "at the piston chamber end of the device is shown with the plug .29 removed and a hand pumping lever v6i! inserted for testing purposes. In this connection als-oan air vent passage 1! (Fig :1) in the body 14 leading off canal 58 is provided with a plug 10 for venting air from the injection fcanals through an angular vent line 12. By opening vent 12 and hand pumping the piston the :fuel lines may be purged of air. The hand lever is provided with 'a hook 13 which engages an extension 14 at the top of the cap 26 for operation of the lever as will be readily understood. The

piston 25 has a central flatted raised surface at sleeve and plunger sub-assembly of the unit. The

remainder of the parts will not need precision workingiof a high caliber in order to operate e'ffectively. The length of travel through the-connecting passageways and canals for compressed air from the combustion space to the piston chamber serves to cool the high temperature air sufliciently and thus in the piston chamber specialized high temperature-resistant alloys are not required. The construction is comparatively simple and economical to manufacture.

The simplicity of the plunger and the counterplunger and its provisions for timing the injection of fuel will be readily appreciated as requir ing a minimum of maintenance and repair work for eflicient operation.

Having described the invention, we claim:

1. Fuel injection apparatus for diesel engine cylinders and the like comprising means for attaching said apparatus to the cylinder head of a diesel engine and including a passage in said means for open communication from the combustion space thereof to said apparatus with a fuel injection line having a valved spray nozzle tip positioned to inject fuel .into said combustion space, a housing supported by said means having a piston chamber and passages thereto in open communication with said passages to the combustion space, a piston in said chamber, a, sleeve in said housing with a fuel chamber therein, a plunger slidably mounted in the sleeve defining one end of said fuel chamber, a counterplunger slidably mounted in the sleeve defining the other end of said fuel chamber, yieldable means engaging said plunger to urge the same outwardly of the sleeve and yieldable mean engaging and urging the counterplunger inwardly of th sleeve, said plunger being engaged by said piston and movable thereby inwardly of the sleeve, said fuel chamber having an inlet opened and closed by movement of the inner outward and inward position respectively of the sleeve and a fuel outlet connected to said nozzle end of said plunger to its .iopenedrandf closed by movement of said countercylinders and the like adapted to utilize the pressure created in the combustion space on the compression stroke of a cylinder and providing the motive power to inject fuel into said combustion space, said apparatus comprising a sleeve having a plunger movable therein and adjacent the innerend of the plunger a fuel inlet port, yieldable means normally urging the plunger outwardly of said sleeve and free of said inlet port to connect said'port with the interior of said -sleeve, a piston chamber at the outer end ofthe plunger Witha piston therein restricting outward extension of said plunger and conduit means providing an unrestricted passage between said piston chamber and said combustion space, said sleeve having a counterplunger slidable therein with its inner end spaced from the end of said plunger and a fuel outlet port adjacent the end "of said counterplunger, yieldable means urging the counterplunger inwardly of said sleeve, said counterplunger having an inward position clos- ,ing off said fuel outlet port, conduit means from said outlet port to said cylinder combustion space including an injector spray valve and nozzle at the end thereof, and mounting means to support :said spray valve to project a spray into said combustion space.

I 3."Fuel injection apparatus for diesel engine cylinders and the like comprising a plunger sleeve having a plunger and counterplunger slidably movable therein with the inner ends of said ,plungers in spaced relation and forming a chamher in the sleeve between said ends, said sleeve being provided with a fuel inlet port adjacent the end of said plunger and a full outlet port adjacent the end of said counterplunger, each of said plungers being movable in the sleeve to close and open the port adjacent thereto, piston means responsive to pressures in the combustion space of a diesel cylinder created by the compression stroke thereof engaging said plunger to move the plunger in the direction of said counterplunger to close said fuel inlet port, yieldable means normally urging said plunger in the opposite direction, said counterplunger being provided with yieldable means normally urging the same towards said plunger andeffecting the closure of said fuel outlet port, conduit means adapted for attachment to the head of a diesel cylinder providing an open passage from the combustion space thereof to said piston means, and fuel injection conduit means with a spray valve and nozzle outlet connected to said outlet port for injecting fuel into said combustion space.

. 4. Fuel injector apparatus for attachment to the head of a diesel engine cylinder and comprisport having its free end being adapted for mounting in the wall of a diesel cylinder and having means for rigidly clamping the support thereto,

an elongated connector member fixed at one end in saidhousing and received in said support with a spray nozzle at the other end for projecting the tip of said nozzle into the combustion chamber of said cylinder, the body of said nozzle and tip being spaced from said connector walls and providing an open passageway to said combustion space, said connector having a fuel injection conduit to said nozzle and an air passage open to said passageway, said housing having a plunger sleeve mounted'therein with a pistonchamber atone end thereof, conduits in said housing connecting said piston chamber with said connector air passage, a piston in said chamber and a plunger movably mounted in said sleeve and engaged at its outer end by said piston, yieldable means urging said plunger outwardly against the piston, said sleeve being provided with a fuel chamber defined at one end by the inner tip of said plunger, a counterplunger movably mounted 'in the sleeve with the inner tip thereof spaced of the counterplunger urging the same inwardly of the sleeve, a fuel inlet port'in the sleeve open to the chamber when its. yieldable means maintains the plunger in its outward position against said piston, a fuel outlet port in the sleeve adjacent the tip of the counterplunger open to said chamber when said counterplunger is urged against its yieldable means outwardly of the sleeve and closed whenurged inwardly of the sleeve by said means, and fuel conduits in the housing and sleeve connecting said outlet port with said connector conduit and including an opening provided in said plunger for registration with the sleeve conduit when said plunger is moved by said piston inwardly of the sleeve. HANS M. KOLSTEE. ANTON F. KOLSTEE. JEAN. E. TUSCHER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,371,787 Ward Mar. 20, 1945 FOREIGN PATENTS Number Country Date 740,599 France Nov. 21, 1932 

